hev: the stone age discussion: http://wordsmith.org/board/showflat.pl?Cat=&Board=miscellany&Number=499. If I click on "show all" I get the 'Lichen on Basalt' thread coming up.
tsuwm: so ... hope that folks obey the "don't post more than 99 posts in a thread" edict

hev, tsuwm, you can still solve that problem even if the "99 psts per thread" has been exceeded. Taking your example, hev, where the post-number in question is 499:

Proceed as you did until the "wrong thread" comes up (and convert that thread to "show all", if it isn't shown in full).
You'll notice that in your browser window, the post-number is not "499" as it should be. (The AWAD software has changed it, thus giving you the wrong thread.)

Put your cursor in the browser window, and manually convert that number to 499; then hit "enter". Voilą!